Objective: To study the effects of Salvia Miltiorrhiza Bung (SMB) on the formation of osteoclast-like cells in vitro. Methods: Mouse bone marrow cells were cultured with α-MEM and exposed to SMB (1.0 g/L), PGE2 (1×10-7 mol/L) or 1.25(OH)2D3 (1 ×10-8mol/L) only, and SMB+PGE2, SMB+1.25(OH)2D3 for 8 d respectively. Tatrate-resistant acid phosphatase (TRACP)-positive cells were detected with Burstone method. Results: The number of TRACP positive cells (mononuclear cells only) in group of SMB was 29.8% of that of the control, that in group of combination of SMB with PGE2was 35.2% of that of group PGE2 alone, and that in group of SMB plus 1.25(OH)2D3 was 39.3% of that of group 1.25(OH)2D3 alone. SMB inhibited the TRACP-positive cells formation only at the concentration of 1.0 g/L, which were not only in mononuclear cells but also in multinuclear cells. In addition, TRACP-positive cells in the groups of 1.25(OH) 2D3 or PGE2 were 6.68 and 6.04 times respectively as that of the controls. Conclusion: SMB has the inhibiting effects on osteoclast-like cells formation, both osteoclasts and their precursors.